Long before the dawn of recorded history, man has cultivated various plants for the nutritional value of their fruits and grains. The majority of important food plants today have originated from three principle regions of the world, namely, the fertile crescents in the Middle East, the southern Chang Jian River valley and Yunnan Province in China, and the relatively arid areas in the foothills of the Andres Mountains in Peru. These areas, while separated by great geographic distances, share one important characteristic, which, in the evolutionary history of plant life on earth, have caused the plants of those areas to develop fruits with relatively large volumes of highly nutritional substances.
In particular, relatively long arid periods in each area cause native plants to evolve survival strategies centering around highly efficient systems for the storage of moisture and nutrition to sustain the development of new plants. Specifically, these systems took the form of large seeds (such as wheat), fruits (such as tomatoes), tubers (such as potatoes) and bulbous root systems (such as onions). Even today, agricultural scientists concentrate their efforts for gathering new genetic breeding materials on these areas of the earth due to the great variety of plants available, only a tiny fraction of which have been commercially developed.
Just about as soon as human populations began the cultivation of food plants, storage and preservation of the same became a primary problem for solution. Food products that cam e from the grasses offered especially promising opportunities in this regard. To those early farmers, grains such as barley, rye, alba and corn must have seemed to have almost unlimited useful shelf life. Thus, Aztec corn and Greek alba both found their way into granaries which were invented in similar fashion on both sides of the Atlantic Ocean. Generally, these storage facilities, which remain unchanged in their essentials since ancient times, are large closed spaces which protect the grain from the adverse environment effects of rain and sun. While the ancients could hardly have suspected the effects of long term exposure to ultra-violet radiation on nutritive value, the more obvious connection between excess moisture and rot suggested keeping grain in closed receptacles, a solution which simultaneously addressed many of the problems associated with other aspects of the deterioration of grains, including ultra-violet deterioration.
One of the most important events in the agricultural history of western man was the discovery, probably in a field of alba, of a particular plant which would come to be known as wheat. An incidental but most important characteristic of this plant was the fact that when a number of grains were rubbed against each other, the coarse shell of the seed, also known as the chaff, would fracture and become disassociated from the kernel. This mutation eventually came to supplant alba almost in its entirety.
As man's use of wheat continued to grow, he came to learn about the preservation of the wheat and the pernicious effects of moisture and dryness. In particular, if wheat was allowed to become too moist, it rotted. On the other hand, if wheat become too dry, it lost flavor and, as learned relatively recently, it also lost nutritional value. Thus, it has long been an object in wheat storage to maintain the maximum possible moisture without encouraging fungal degradation of the grain.
It also came to be learned that the best way of judging the moisture content of the wheat is by the color of the grain. Thus a skilled granger periodically checks wheat from various parts of the granary and observes the color thereof from which he can judge the moisture content of the grain. In recent years, higher moisture contents can be maintained by, for example, fumigation of the grain with anti-fungal agents. In addition, while economically impractical, grain moisture content can be maintained at a high level by refrigeration of the grain.
More recently, less precise methods of visual observation of grain color have been replace by the measurement of grain color using optical instrumentation. Such instruments as spectrum analyzers compare light from a standard sample of grain of known humidity which is hermetically housed behind a sodium chloride window. Light reflected by an unknown sample is analyzed and the spectral content of the reflected light is compared to the reflected by standards of known humidity to find a match, thus indicating that the unknown has the same humidity as the known matched standard sample.
Unfortunately, such standard samples are very expensive to manufacture and have extremely limited life. Accordingly, they must be constantly replaced at great cost. The present invention has the object of dispensing with this difficulty.